As the Prince lays the new stone at the Cottage Hospital, McDuff drops trou, and Isobel and Charlotte arrive nude on Brass Beauty to protest the rent increase. Suddenly, the mortar on the trowel explodes — SBD. All are covered in foam -–Jack saves Big Tom with his truss flange. Bradley and Austin realise Morris was behind the explosion, so Bradley plans to send him to Australia.

Charlotte inherits a large sum of money on her birthday. Jack refuses a deal with Austin. Guy tells Morris that Moscow wants him as a mole in the church while Agnes complains to McDuff about George's increased libido. Matt and Charlotte agree to be friends, not lovers. McDuff discovers SBD increases sexual activity in rabbits.

McDuff decides SBD is a hallucinogen. Bradley pays Jack for his work on Big Tom and offers him the lease on the crutch works. Bradley goes to sack the infant schoolteacher but instead is struck dumb by Cupid's dart and invites her to play piano at the hall. The Fairchilds spurn Jack's offer of work, informing him of his traitorous actions.

Morris confronts Matt about his homosexuality, who doesn't deny it but claims celibacy. Jack declares his love for Charlotte but she rejects him, wishing he was Matt. Isobel proclaims her continuing love for Jack as Lady Patience tells her not to marry Mountfast. Austin and Isobel go hunting for rent defaulters but are foiled by Matt and Charlotte.

Austin tells the family he thinks Bradley is insane. McDuff says that the cause of a raging epidemic raging is the convenience at the back of the munitions factory. Bradley gives Prudence SBD and then takes advantage of its effects. Bradley tells George to keep using the convenience, and McDuff and Agnes wire it up to explode.

Bradley gets out of being certified and turns the tables on Austin. George, blackened but alive, returns home. Bradley decides to sort out Pugh and help Austin win the election, with the help of Mrs Marchington, his father's chiropodist, and SBD.

Austin hears Sodbury has died at the chiropodists, which means Pugh will go to the House of Lords and it will be a walkover for him at the by-election. Jack fails to dissuade Isobel from marrying Mountfast, but she guesses he's done a deal with her mother.

Bradley tells Austin he is to marry Cynthia Dudcock. Bradley offers to send Man to Paris to paint, as long as he goes with Agnes, but Matt sees through it. Jack asks Charlotte to marry him but she refuses. McDuff tells Lady Patience of Bradley's plans to expose photos to the BMC, and she tells him how to retrieve them.

Hardacre looks at Mountfast's body — Sergeant Pepper says a tramp will have done it. McDuff says his brother Inspector McDuff of the Yard is in the area. George tells Agnes of his new position in the UCTT. Charlotte tells Agnes she feels ill in the mornings. Matt says there's no money to fight the election and Jack offers to help them.

Charlotte and Isobel visit Lady Patience in prison to inform her she's to have the finest defence lawyer. Job shows George and Agnes the official union vehicle: a tandem. Bradley refuses to pay for Lady Patience's defence, so Isobel seeks the services of Marshall Snelgrove of the Queen's Counsel. Meanwhile, Agnes tells Austin she's going to carry an with the election. Guy tells Morris that Moscow wants Hesketh to fight in the Spanish Civil War.

During round table discussions, Bradley tells George pithead baths will be installed in order to get workforce on strike. Lady Patience's trial takes place and she is called to the witness box. Bradley asks Charlotte to return home. Lady Patience tells the court how she visited Mountfast on the night of the murder and he was so appalled by his debauchery that he committed suicide.

Charlotte receives a solicitor's letter saying she'll inherit Mountfast's money. Bradley is informed by future Tory MP his earldom is no-go, so he decides to join the other side. Isobel is distressed about Mountfast's inheritance and is seared that Jack will propose to Charlotte, which is exactly what he does.

Bradley and Jack rejoice in the arms sales boosted by the Spanish Civil War but Bradley feels a world war would be better. Charlotte is distraught having read that Matt's been killed in Spain, and gives birth to a boy. Guy informs Morris that Stalin wants Bradley out of the way and gives him cyanide to poison Bradley. Matt appears, saying Hesketh was shot in Spain.